docs: def delete(gandi, resource, force, background):
      """ Delete a disk. """
      output_keys = ['id', 'type', 'step']
  
      resource = sorted(tuple(set(resource)))
      if not force:
          disk_info = "'%s'" % ', '.join(resource)
          proceed = click.confirm('Are you sure you want to delete disk %s?'
                                  % disk_info)
  
          if not proceed:
              return
  
      opers = gandi.disk.delete(resource, background)
      if background:
          for oper in opers:
              output_generic(gandi, oper, output_keys)
  
      return opers